This invention relates to dynamoelectric machines, and particularly to such machines having one of the rotor and stator including electromagnetic wound poles and the other of the rotor and stator including permanent magnets on a magnetic core. The sintered magnets used in such machines are generally arcuate in shape and attached to a cylindrical core with adhesive. However, due to the distortions occurring in the sintering of a relatively thin part, magnets must have their arcuate surfaces finished by a grinding process; and this grinding process itself leaves a surface which is not truly arcuate, but includes high and low points. Likewise, the part of the core to which the magnet is attached may have been formed from a die which was ground and includes similar high and low points. Thus the parts do not meet precisely over the full mounting surface; and the adhesive is thus squeezed out of the areas of high points for a non-uniform attachment. In addition, the varying gap creates non-uniform magnetic flux across the boundary.
A solution to this problem of non-uniform arcuate surfaces in permanent magnets used in dynamoelectric machines must, however, also take into account the axial skew in the magnetic poles, which skew is introduced to reduce magnetic flux variations and resulting audible noise created during rotor rotation.